<!Doctype html>
<html>
<head>
	<meta charset="utf-8" />
	<title></title>
</head>
<body>
	
	<div id="box" class="box">
		<p id="test">
		This is a Paragraph!
		</p>
	</div>
	<input type="button" value="点我" onclick="BMI()">
	<script>
		function BMI() {
			var height=prompt('Please enter your height');
			var weight=prompt('Please enter your weight in KG')
			var BMI=weight/(height*height);
			console.log(BMI);
		}
	</script>
</body>
</html>